This invention relates to means for monitoring the liquid level in a container.
A common form of container for the storage and transport of liquid is one in which there is a pallet type base on which there is mounted four interlocked side panels. The side panels are typically metal frames covered with an opaque plastic sheet material which incorporates a UV inhibitor. The side panels can be demountable from the base or can be hinged thereto so that the side panels can fold down over each other and over the base. The side panels when erected on the base provide an open topped enclosure for a clear plastic film liner bag. The word xe2x80x9cclearxe2x80x9d in the context of the present invention means a plastic liner sufficiently transparent to allow the level of liquid housed in the bag to be seen. A lid is provided for the open top of the container. Discharge is by gravity through a nozzle of the liner big which projects through an opening in one side panel of the container at an elevation slightly above the bag supporting upper face of the base of the container. The nozzle is adapted for the connection of a valve and a discharge pipe.
In use, means to readily ascertain the amount of liquid in the liner big in the container at any one time is desirable. This can be done by knowing the amount of liquid in the container before emptying, measuring the amount discharged and subtracting the latter from the former. Another method is to use a dip stick through the filler nozzle in the top of the liner bag.
Neither method readily provides the information required. It is also desirable to know what liquid is in the liner bag, eg. hazardous, benign, acidic, alkaline, etc.
The present invention proposes the inclusion of a xe2x80x9cwindowxe2x80x9d in a side of the container which may carry indicia to accurately indicate the quantity of liquid in the liner bag. By means of a coding system, for example colour coding, the nature of the liquid in the liner bag can be readily determined. To allow ready changeover of the window, to allow for different indicia or colour coding, or to allow replacement of the window in the case of damage, the window is made readily removable from the container side.
For practical reasons, it is not possible where plastic sheet material is used to cover the frames of the side panels to make that plastic transparent to act as a window, One reason is that it would be too difficult to have a whole side covering sheet readily removable. Another reason is that where plastic sheet material is used to cover the container sides economics dictates that the sheet must be of low cost and such low cost plastic sheet material requires a UV inhibitor because the containers are often placed in positions where they are exposed to sunlight. If the UV inhibitor was to be added to a clear plastic sheet of conventional (cost effective) material the sheet material would be rendered translucent thereby making it useless as a means for observing the liquid level in the film bag in the container. Some plastics, such as polycarbonate and PETG, can withstand UV effects whilst remaining substantially transparent such material is however too expensive to use to completely cover the frames of the container side panels. The present invention addresses the above requirements in a simple and economic manner.
Broadly stated the invention can be said to provide an inspection side panel for a container to house a clear plastic liner bag adapted to hold a liquid, said side panel including a segment extending for substantially the whole height of the said side panel, the segment is readily removable in order to allow replacement and is substantially transparent.
In another, specific, form the invention provides an inspection side panel for a container, where said side panel includes a demountable substantially transparent UV ray resistant sheet plastic inspection segment extending for substantially the whole height of the said side panel, where the segment is adapted for use in combination with three other side panels and a base to form a container to house a clear plastic liner bag for liquid, wherein the base is a rectangle with two plinths of the same height upstanding from a support surface of the base along two opposed side edges of the base, said side panels being arranged in pairs with one pair shorter than the other by the amount that top edges of the plinths stand above the base support surface, the shorter side panels are respectively coupled to said plinths so as to be able to be moved between overlying relationship over said base and an upright condition relative to the base and the taller side panels one of which includes said inspection segment are respectively coupled each to both plinths at the other side edges of said base so as to be able to be moved between overlying relationship over said base and an upright condition relative to the base and releasable securing means is provided to secure together adjacent side panels when upright relative to the base.
More specifically, the invention can be said to provide an inspection side panel for a container, where said side panel includes a demountable transparent inspection segment extending for substantially the whole height of the said side panel, in combination with other side panels and a base to form a container to house a clear plastic liner bag for liquid, where all the side panels are of substantially the same height and are adapted with the base to allow the side panels to be mounted on and demounted from the base releasable securing means is provided to secure together adjacent side panels mounted on the base.
The facility of ready replacement of the segment allows the versatility of the container to be improved. Not only can the segment be easily replaced if damaged, substitution of the segment by a segment of having unique characteristics to suit use requirement is possible. For example, segments having graduations of different types (metric volumetric measure or imperial volumetric measure) are possible. Different scales of graduation are possible, xe2x80x9cfullxe2x80x9d, xe2x80x9cxc2xe fullxe2x80x9d, xe2x80x9cxc2xd fullxe2x80x9d, xe2x80x9czeroxe2x80x9d, would be an example, as distinct from xe2x80x9c1000 litresxe2x80x9d, xe2x80x9c900 litresxe2x80x9d, etc. being the other possibility. Colour coded segments to indicate the nature of the liquid in the liner bag (hazardous, benign, acidic, alkaline, etc.) are possible. Coloured segments to protect light sensitive liquid in the liner bag are possible.